US 4,414,113 AGranted

Liquid purification using reverse osmosis hollow fibers

AssigneeEcodyne Corporation

InventorTerrance LaTerra

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Abstract

A method and apparatus for removing dissolved solids from a liquid which utilizes the technique of reverse osmosis (RO). The liquid to be treated is directed into a pressure vessel which contains a plurality of filter elements positioned therein. The filter elements have hollow RO fibers wound around foraminous center cores such that the liquid flows in a direction from the outside of the filter elements towards the center cores. The pure permeate liquid passes into the center bores of the fibers and the concentrate liquid passes into the center cores of the elements. The method and apparatus provide for the backwashing of the filter elements when they become fouled. Further, an outer filter septum may be applied around the hollow RO fibers of the elements to remove particulate matter which would otherwise foul the hollow RO fibers.

Claims15

Dependent claims

A method for removing dissolved solids and suspended particuate matter from a liquid to be treated, comprising the steps of:

(a) passing a feedstream of liquid to be treated into a pressure vessel having a plurality of filter elements vertically positioned therein;
(b) directing the liquid to be treated through an outer filter septum positioned around the filter elements for removal of suspended particulate matter in the liquid to be treated;
(c) directing the liquid to be treated that passes through the filter septum through a layer of hollow RO fibers spirally wrapped around formaninous center cores of the filter elements such that the liquid to be treated flows in a direction from the outside of the filter elements towards the foraminous center cores, so as to cause substantially pure permeate liquid to permeate into the center bores of the hollow RO fibers and concentrate liquid to pass into the foraminous center cores;
(d) collecting the permeate liquid from the center bores of the hollow RO fibers in a common collector manifold and removing the collected permeate liquid from the pressure vessel;
(e) collecting at least a portion of the concentrate liquid from the center cores in a common concentrate liquid collection compartment and removing the collected concentrate liquid from the pressure vessel;
(f) periodically terminating passage of the liquid to be treated into the pressure vessel and directing backwash liquid into the concentrate liquid collection compartment and then across the layer of hollow RO fibers and the filter septum into the pressure vessel, so as to remove particular matter that is trapped in the hollow RO fibers and the filter septum and;
(g) removing the backwash liquid along with the suspended particulate matter from the pressure vessel.

4 more elements

An apparatus for removing dissolved solids and suspended particulate matter from a liquid to be treated, comprising:

(a) a pressure vessel having a tube sheet which divides said pressure vessel into an upper influent compartment and a lower concentrate compartment and a collector manifold which is positioned in an upper portion of said influent compartment;
(b) a plurality of vertically extending filter elements each extending between said tube sheet and said collector manifold, said filter elements each having foraminous center cores which extend through said tube sheet into and in fluid communication with said concentrate compartment;
(c) a layer of hollow RO fibers spirally wrapped around said center cores, said hollow RO fibers having center bores in fluid communication with said collector manifold;
(d) a filter septum means positioned around each of said layers of hollow RO fibers for removing suspended particulate matter from liquid passing therethrough;
(e) means for directing a feedstream of liquid to be treated under pressure into said influent compartment of said pressure vessel such that the liquid to be treated flows in a direction from the outside of the filter elements through said filter septum means for removing particulate matter and then through said layer of hollow RO fibers for causing substantially pure permeate liquid to permeate into the center bores of said hollow RO fibers and concentrate liquid to pass into said foraminous center cores;
(f) means for directing the permeate liquid in the center bores of said hollow RO fibers into said collector manifold and removing the permeate liquid in said collector manifold from said pressure vessel;
(g) means for directing the concentrate liquid in said foraminous center cores into said concentrate compartment and removing at least a portion of the concentrate liquid in said concentrate compartment from said pressure vessel;
and
(h) backwash means for periodically passing backwash liquid into said concentrate compartment and up into said foraminous center cores and then outward across said layer of hollow RO fibers and said filter septum means into said influent compartment for removing particular matter that is trapped in said hollow RO fibers and the filter septum means.

6 more elements

Dependencies are inferred from the claim text.